Renewable Energy from Food Residuals

Food residuals are an untapped renewable energy source that mostly ends up rotting in landfills, thereby releasing greenhouse gases into the atmosphere. Food residuals are difficult to treat or recycle since it contains high levels of sodium salt and moisture, and is mixed with other waste during collection. Major generators of food wastes include hotels, restaurants, supermarkets, residential blocks, cafeterias, airline caterers, food processing industries, etc.

food-waste

In United States, food scraps is the third largest waste stream after paper and yard waste. Around 12.7 percent of the total municipal solid waste (MSW) generated in the year 2008 was food scraps that amounted to about 32 million tons. According to EPA, about 31 million tons of food waste was thrown away into landfills or incinerators in 2008. As far as United Kingdom is concerned, households throw away 8.3 million tons of food each year. These statistics are an indication of tremendous amount of food waste generated all over the world.

The proportion of food residuals in municipal waste stream is gradually increasing and hence a proper food waste management strategy needs to be devised to ensure its eco-friendly and sustainable disposal. Currently, only about 3 percent of food waste is recycled throughout U.S., mainly through composting. Composting provides an alternative to landfill disposal of food waste, however it requires large areas of land, produces volatile organic compounds and consumes energy. Consequently, there is an urgent need to explore better recycling alternatives.

Anaerobic digestion has been successfully used in several European and Asian countries to stabilize food wastes, and to provide beneficial end-products. Sweden, Austria, Denmark, Germany and England have led the way in developing new advanced biogas technologies and setting up new projects for conversion of food waste into energy.

Anaerobic Digestion of Food Waste

Anaerobic digestion is the most important method for the treatment of organic waste, such as food residuals, because of its techno-economic viability and environmental sustainability. The use of anaerobic digestion technology generates biogas and preserves the nutrients which are recycled back to the agricultural land in the form of slurry or solid fertilizer.

The relevance of biogas technology lies in the fact that it makes the best possible use of various organic wastes as a renewable source of clean energy. A biogas plant is a decentralized energy system, which can lead to self-sufficiency in heat and power needs, and at the same time reduces environmental pollution. Thus, anaerobic digestion of food waste can lead to climate change mitigation, economic benefits and landfill diversion opportunities.

Of the different types of organic wastes available, food waste holds the highest potential in terms of economic exploitation as it contains high amount of carbon and can be efficiently converted into biogas and organic fertilizer. Food waste can either be used as a single substrate in a biogas plant, or can be co-digested with organic wastes like cow manure, poultry litter, sewage, crop residues, slaughterhouse wastes, etc.

A Typical Food Waste-to-Energy Plant

The feedstock for the food waste-to-energy plant includes leftover food, vegetable refuse, stale cooked and uncooked food, meat, teabags, napkins, extracted tea powder, milk products, etc. Raw waste is shredded to reduce to its particle size to less than 12 mm. The primary aim of shredding is to produce a uniform feed and reduce plant “down-time” due to pipe blockages by large food particles. It also improves mechanical action and digestibility and enables easy removal of any plastic bags or cling-film from waste.

Fresh waste and re-circulated digestate (or digested food waste) are mixed in a mixing tank. The digestate is added to adjust the solids content of the incoming waste stream from 20 to 25 percent (in the incoming waste) to the desired solids content of the waste stream entering the digestion system (10 to 12 percent total solids). The homogenized waste stream is pumped into the feeding tank, from which the anaerobic digestion system is continuously fed. Feeding tank also acts as a pre-digester and subjected to heat at 55º to 60º C to eliminate pathogens and to facilitate the growth of thermophilic microbes for faster degradation of waste.

From the predigestor tank, the slurry enters the main digester where it undergoes anaerobic degradation by a consortium of Archaebacteria belonging to Methanococcus group. The anaerobic digester is a CSTR reactor having average retention time of 15 to 20 days. The digester is operated in the mesophilic temperature range (33º to 38°C), with heating carried out within the digester. Food waste is highly biodegradable and has much higher volatile solids destruction rate (86 to 90 percent) than biosolids or livestock manure. As per conservative estimates, each ton of food waste produces 150 to 200 m3 of biogas, depending on reactor design, process conditions, waste composition, etc.

Biogas contains significant amount of hydrogen sulfide (H2S) gas that needs to be stripped off due to its corrosive nature. The removal of H2S takes place in a biological desulphurization unit in which a limited quantity of air is added to biogas in the presence of specialized aerobic bacteria that oxidizes H2S into elemental sulfur. The biogas produced as a result of anaerobic digestion of waste is sent to a gas holder for temporary storage. Biogas is eventually used in a combined heat and power (CHP) unit for its conversion into thermal and electrical energy in a co­generation power station of suitable capacity. The exhaust gases from the CHP unit are used for meeting process heat requirements.

The digested substrate leaving the reactor is rich in nutrients like nitrogen, potassium and phosphorus which are beneficial for plants as well as soil. The digested slurry is dewatered in a series of screw presses to remove the moisture from slurry. Solar drying and additives are used to enhance the market value and handling characteristics of the fertilizer.

Diverting Food from Landfills

Food residuals are one of the single largest constituents of municipal solid waste stream. Diversion of food waste from landfills can provide significant contribution towards climate change mitigation, apart from generating revenues and creating employment opportunities. Rising energy prices and increasing environmental pollution makes it more important to harness renewable energy from food scraps.

Anaerobic digestion technology is widely available worldwide and successful projects are already in place in several European as well as Asian countries that makes it imperative on waste generators and environmental agencies to root for a sustainable food waste management system.

Best Ways for Your College to Go Green

Today a lot of colleges have made an environmental revolution. No more coffee to go, no more plastic bottles to buy on a territory of the campus, the implementation of eco-friendly projects and campaigns – all this now is becoming a sustainable lifestyle for the majority of students.

The effects of climate change are dramatically terrifying. In most colleges, the initiative of the activities to make planet safer comes from administration faculties. However, any little action of every student will help to protect our Earth. Let’s see now how green we may be in a range of college life.

college-green

Today you even may look for the university that has its degrees in eco subjects: such as sustainable agriculture, natural resources conservation and indoor gardening and so on.

Energy supply

Whether it is a constructing of building with more efficient environmentally substantial windows and panels that use solar, wind or even water power, during past several years the colleges become a way eco-friendlier. Some programs promote the conservation in any aspect and the composting bins.

Using electronics instead of paper

The world now is digitally focused, and this is good news for a planet. A lot of colleges are equipped with computer classes, electronic libraries, and online testing programs. You may also have with taking notes electronically in order not to waste paper and money on buying notebooks. Instead of buying a book, prefer to borrow it or get only if necessary.

To see and read more more living a sustainable and healthy life, check out the Public Goods Blog by clicking here.

Opening a refectory with a local eco food

Organic food and organic gardening is a modern, healthy part of a sustainable lifestyle. The most colleges now have the individual spaces for organic gardening where any student can work to show their faith-based actions. They can grow plants, vegetables or fruits that are used in the kitchen of the campus for preparing healthy food.

The administration of some universities now got rid of trays – they state it will prevent students from over-eating and wasting food. Instead, a student takes a plate where he can put only as much as he can eat.

Having a place for refilling a water bottle

As you know, only 20% of plastic bottles will be recycled. Tthe question is that where did other 80% proceed to? The management of some colleges take concrete measures to fight this issue: they don’t sell plastic bottles on the territory of campus. As an alternative, they give reusable water bottles and provide with stations of water filling. Isn’t it an amazingly simple and useful to evolve an initiative to become environmentally conscious?

Special campaigns for students

It is important for colleges to have some green project ideas for college students that may evolve students to concrete actions toward the protection of an ecology. It can be something like tree planting, street cleaning or any other environment-themed campaigns.

Organic food is a modern, healthy part of a sustainable lifestyle.

Organic food is a modern, healthy part of a sustainable lifestyle.

The effective way to make the more environmentally sustainable community is creating a communication between students and management. Every student may have his fresh ideas of go green, and it ‘d be good and if the management could encourage them and help to realize.

Transportation

What doesn’t student dream of having his car? But don’t lie to yourself – it is not a secret that the cars are the biggest reason of pollution in the air. Just think about it – do you need a car? Taking a public transport or having a bicycle will not only save a planet but also will save your money.

Many colleges offer carpool boards which allow pairing riders with drivers and a shuttle bus which run on biodiesel that is much safer for the planet than any other fuel.

Good old recycling

Almost every college has recycling bins and trash cans on its territory. The faculty and staff should be responsible for what and where they throw away – it will be a good example for every student.

Creating eco-friendly rules in a campus

  • Turn off everything
  • Using LED light bulbs
  • Reduce, reuse, recycle
  • Water-usage control (only a 5-minute shower)
  • Buy recyclable and eco products, e.g. you can even find eco friendly wooden watches these days.
  • Use power bars
  • Wash cups and plates, don’t use disposable paper or plastic utensils
  • Walk, bike and use public transport instead of a car

If you at a moment of decision which higher educational institution to choose – go ahead to pick a “go green” university which has at least some of point mentioned above!

Don’t close your eyes to truth – the climate change, the nuclear waste, etc.

With all these actions, even the little ones, we may protect the environment together and live a sustainable life!

If this article written by a birdie essay writer was helpful and met your expectations – you can find other related works and even obtain help with your essay if needed!

Wish you a good green luck!

Tips for Creating a Better Waste Management Plan in 2020

People are more environmentally conscious than ever, and want to do their part to help reduce waste. Not only are they themselves eco-friendly, but they also want the companies they purchase from and support to do their part as well. Nearly every company will produce some type of waste, despite their best intentions. Even things like offices can create a lot of waste. This waste can have a terrible impact on the environment, for everything from wildlife to our own public health.

However, producing zero waste isn’t always possible for companies (at least not currently). As a result, it is more important than ever to have a good waste management plan for your business. These plans help you deal with responsibly getting rid of waste, as well as reducing it where possible.

Unfortunately, crafting one isn’t always easy. Thankfully, we are here to help. This article is going to go over some great tips for creating a better waste management plan in 2020.

Do Your Due Diligence

First and foremost, you need to perform an adequate amount of due diligence. While some companies might think they know all of the waste that they are producing, that isn’t always the case. There could be remnants of waste on your property from years ago, which could be damaging the soil and the environment.

In order to truly get the full picture of the waste you are creating or have created, you need to have testing, site-walks and other types of due diligence conducted. The more you know about the kind of waste you are creating, and how much, the better suited you will be to build out your customized plan.

Whether you are an established company wanting to improve or create your plan, or a company looking for a new workplace or site, doing due diligence is a must. If you want to learn more about this environmental due diligence, and the assessments involved, you can do so in this Phase I Environmental Site Assessment article.

Find Ways to Reduce and Reuse

While responsibly disposing of things is often at the heart of any waste management plan, it should be about so much more than that. In fact, actually throwing things away at a dump or landfill should be kept to a minimum. Instead, your plan should be focused primarily on reducing your waste and reusing what you can.

This could be by changing up certain processes, using new technology, or simply identifying what methods produce the most waste, and optimizing them. Also seek to reuse the waste that you can. If you yourself can’t use it, see if another company or industry might be able to.

For example, instead of tossing food waste in the garbage, it can often be used as compost by large farms. While not all types of waste can be reduced or reused, you would be shocked at what can be done if you take your time and come up with a plan.

Know the Responsibilities and Guidelines in Your Area

In most areas, businesses have certain responsibilities when it comes to waste management. It could be anything from offering the right receptacles to staying below a certain threshold of waste. You need to be aware of your responsibilities wherever you operate. If you don’t comply and do what you are responsible for doing, you could end up with some serious penalties or fines to deal with.

In addition to knowing the responsibilities you have in your local area, also be aware of the guidelines. Some cities or areas will require the waste to be sorted or disposed of in a certain way. Be sure to have all of these policies and rules clearly stated for everyone, so they aren’t left confused about anything.

On a similar note, be aware of the local services that can assist with waste management. Know where they operate, what sorts of materials they can help you dispose of and what the associated costs are.

In conclusion, we hope the information and tips in this article have helped you create a better waste management plan in 2020.

Waste Management Perspectives for Military

Waste management has a profound impact on all sections of the society, and military is no exception. With increasing militarization, more wars and frequent armed conflicts, protection of the environment has assumed greater significance for military in armed conflicts as well as peacetime operations. Tremendous amount of waste is generated by military bases and deployed forces in the form of food waste, papers, plastics, metals, tires, batteries, chemicals, e-waste, packaging etc.

War on Waste

Sustainable management of waste is a good opportunity for armed forces to promote environmental stewardship, foster sustainable development and generate goodwill among the local population and beyond. Infact, top military bases in the Western world, like Fort Hood and Fort Meade, have an effective strategy to counter the huge amount of solid waste, hazardous waste and other wastes generated at these facilities.

Waste management at military bases demands an integrated framework based on the conventional waste management hierarchy of 4Rs – reduction, reuse, recycling and recovery (of energy). Waste reduction (or waste minimization) is the top-most solution to reduce waste generation at military bases which demands close cooperation among different departments, including procurement, technical services, housing, food service, personnel. Typical waste reduction strategies for armed forces includes

  • making training manuals and personnel information available electronically
  • reducing all forms of packaging waste
  • purchasing products, such as food items, in bulk
  • purchasing repairable, long-lasting and reusable items

Due to large fraction of recyclables in the waste stream, recycling is an attractive proposition for the armed forces. However, environmental awareness, waste collection infrastructure, and modern equipment are essential for the success of any waste management strategy in a military installation.

Food waste and yard waste (or green waste) can be subjected to anaerobic digestion or composting to increase landfill diversion rates and obtain energy-rich biogas (for cooking/heating) and nutrient-rich fertilizer (for landscaping and gardening). For deployed forces, small-scale waste-to-energy systems, based on thermal technologies, can be an effective solution for disposal of combustible wastes, and for harnessing energy potential of wastes. In case of electronic wastes, it can be sent to a Certified Electronics Recycling and Disposal firm.

Key Aspect

Management options for military installations is dependent on size of the population, location, local regulations, budgetary constraints and many other factors. It is imperative on base commanders to evaluate all possible options and develop a cost-effective and efficient waste management plan. The key factors in the success of waste management plan in military bases are development of new technologies/practices, infrastructure building, participation of all departments, basic environmental education for personnel and development of a quality recycling program.

Military installations are unique due to more than one factor including strict discipline, high degree of motivation, good financial resources and skilled personnel. Usually military installations are one of the largest employers in and around the region where they are based and have a very good influence of the surrounding community, which is bound to have a positive impact on overall waste management strategies in the concerned region.

Zero-Waste Trends in the United States

Most people don’t see what happens to their trash. They throw it in a black plastic bag, toss the bag into a dumpster and the trash man collects it once a week and makes it disappear. Magic, right?

Wrong.

Most of our trash ends up in a landfill where it is buried and mixed in with decades-worth of junk. Certain items will break down over time while others are essentially just stored there, in a graveyard of forgotten items and a mountain of garbage.

In the year since China banned the import of other countries’ plastic recyclables, the global recycling industry has been in flux, resulting in plastics ending up in landfills, incinerators and littering the environment. This is causing countries and citizens across the globe to reexamine their recycling systems and highlights the need for zero waste practices.

Zero waste is the concept of eliminating the amount of trash thrown away by only purchasing reusable items. That’s a significant shift from the 4.4 pounds of trash that the average American tosses every day. But certain trends are helping make the idea of zero waste a reality in the United States. Let us have a look:

Replace Single-Use Packaging With Reusable Materials

Way too many plastic items that we use every day are meant to be used only once. And the amount of packaging that goes into shipping one box, that will simply get tossed in the garbage after the parcel is unwrapped, is astounding. In fact, 40 percent of plastic produced is packaging, which is thrown away after it arrives at your doorstep.

Plastic bag and straw bans are on the rise across the globe. Consumers are becoming more conscious of how their use of these items contributes to the trash crisis. Recent data shows that customers are more likely to buy products from brands that promote sustainable business practices.

Reduce Energy Waste By Choosing Renewable Options

Many industries are opting to reduce energy waste by pursuing renewable energy sources. U.S. manufacturers account for 30 percent of the nation’s energy consumption, which means manufacturers must take the lead in reducing fossil fuel consumption and energy waste.

The U.S. is the leader in energy waste. Americans spend $350 billion on energy costs each year, yet three-quarters of that energy goes to waste. One way to reduce the burden on our power grid — and our wallets — from all that lost energy is by switching to renewable sources.

Air compressors are vital to the upkeep of a successful farm, and many producers in the agricultural sector are also reducing waste by switching to high-powered air compressors that, when properly maintained, can reduce energy usage and cut costs.

Eliminate Food Waste

About 94 percent of food waste ends up in landfills, which contribute to methane gas emissions. Reducing food waste not only helps the environment, but it also decreases the amount you have to spend at the grocery store. It also helps to conserve energy, as less power is needed to grow and produce food if less is wasted.

Individual consumers can help eliminate food waste by freezing leftovers to preserve them and composting uneaten food, as opposed to tossing in the trash.

Restaurants can use these tactics and others to cut down on food waste, such as donating leftovers and properly training staff to get on board with waste reduction. They can also hire auditors to help them identify ways to reduce waste and streamline business practices.

Never Too Late to Make a Change

Though the statistics may seem disheartening, the reality is that it’s never too late to make a change in your individual or business habits to help cut down on waste and work toward the goal of accomplishing zero waste. Following these trends and implementing others is just one way to do your part to eliminate waste and protect the environment.

Top 5 Tips For Reducing Waste in Your Home

Reducing waste in your home is more important now than ever. As the environment is becoming more in danger because of greenhouse gases, climate change, and pollution, the need for humans to reduce their carbon footprint is imperative. However, even if people want to make an effort to save the environment, many people don’t know where to start and how to go about changing their everyday lives in order to become more eco-friendly.

Starting in your home is a great way to begin working towards an eco-friendly lifestyle. A custom home builder in Cherry Hill New Jersey, said, “Making your home environmentally savvy can mean installing something as large as solar panels or it can mean something much smaller; like using reusable shopping bags at the grocery store and not buying plastic products. Either way, making your home eco-friendly is important.”

Reducing waste in your home is easy and will have an outstanding impact on the environment. Here are some quick and easy tips to keep in mind that will help you reduce waste in your home:

1. Start Composting

Starting a compost pile creates less trash by recycling leftover food that would otherwise go in the trash. The point of a compost pile is to put the leftover, and even expired, food back into the earth rather than letting it sit in the garbage or in landfills.

compost_strategies

A compost pile is easy to start, all you need is a bin and some extra space. After you’re done eating something (as long as it isn’t meat, a milk product, or greasy processed food), you can put it in this bin and then incorporate it into your garden or yard every few weeks. Your food won’t go to waste and your garden/yard will get the nutrients it needs.

2. DIY Beauty and Household Products

Buying less plastic products is another great way to reduce waste in your home. However, most beauty and household products are packaged in plastic containers which makes reducing plastic in this way a major obstacle.

A possible solution to this issue is making your own beauty and household products like floor cleaner, deodorant, and toothpaste. Though buying the ingredients to make these products may create a small amount of waste, the ingredients are easier to buy in bulk so you will have to buy them less frequently and will be able to create ample amounts of beauty and household products.

Creating homemade products is also a great way to ensure you aren’t getting chemicals in your products that are damaging to the environment and will create waste or harmful toxins.

3. Meal Plan

Food waste is a huge issue in households. Often, between ¼ to ½  of a household’s weekly produce, meats, and milk products are thrown out at the end of the week. This is preventable with the incorporation of meal planning and meal prepping in your life. By starting a meal plan, you will only buy what you need and will be less likely to waste products because they expired.

food-waste-management

This will generate less waste in terms of food that will end up sitting in a landfill but also in terms of plastic packaging waste that food is packaged in.

4. Repair Instead of Replace

This is an easy way to create little waste in your home that many people don’t think about. When something in your home breaks, whether it is a small kitchen appliance or something large like a heater or part of a couch, take the time to repair it instead of getting a new one. If you repair an item, the original one won’t make its way to a landfill and you will get more life out of your products.

If an appliance or piece of furniture is unable to be repaired, make an effort to recycle some of the important parts; or, if you are in the market to buy a replacement, look online for used products or go to a secondhand store. This will create less waste and will also save you money.

5. Cancel and/or Recycle Junk Mail

Easy and free, by canceling and recycling junk mail will immediately reduce waste in your home. Most people don’t even look at the junk mail and toss it right in the garbage can. Canceling subscriptions only requires a phone call or email and will significantly cut back the waste that is generated in your home.

If you receive junk mail that is not sent to you via subscription and you are unable to cancel it, make sure to at least recycle it.

Eliminating junk mail will also help with decluttering your coffee tables and countertops, an added benefit to helping the environment.

Bottom Line

There is always room for improvement when trying to improve your lifestyle in terms of creating less waste. These tips are a great way to start making an impact on saving the environment before it’s too late. Reduce the waste in your life with minimal effort and small, simple changes.

5 Best Things Students Can Do to Save the Planet

Like anyone else, students have an important role to play in counteracting current environmental problems. After all, they are the generations that would unjustly inherit some of the most perilous global challenges humanity has ever faced. They would also become the future leaders that are expected to implement key measures to save the planet in the coming decades. Below, we explore the most important means through which students can help the ongoing fight. For some key advice on how each of us can contribute, check this info guide from the World Wildlife Fund.

1. Consume Less

If there is one thing you must do before everything else in order to save the world, it is limiting the number of resources you require. This applies to most products – there are very few exceptions. It is crucial to reduce the amount of environmentally damaging products consumed, such as plastics in any form, various chemical products (detergents, bleach, cosmetics), industrial products, especially those that use valuable resources, are hard to recycle, or whose production is associated with high energy demands.

By reducing consumption, you can also save money, which is always relevant for a student. Given how our world and economy function, every time you buy something you cast a vote for a particular version of the future.

2. Recycle

Although probably having the greatest impact, avoiding consumption entirely is unrealistic or incredibly hard to achieve. Hence, for those products that you do consume, seek for ways to recycle them. Food waste can be turned into compost, while plastic, paper, metal, the glass could all be reused.

Also, ensure that you support producers that recycle materials. Even so, you should be aware that recycled materials are typically used only in producing lower-quality or less demanding industrial products, hence, it is not ensuring a closed circuit of resources.

3. Mind What and How Much You Eat

Even if food waste isn’t normally a polluting factor, the production of any food requires significant amounts of water, energy, fertilizers, pesticides, herbicides, and fossil fuels. Hence, when throwing food away, we waste considerable resources.

Apart from that, there are some foods that are associated with a much higher environmental impact, such as palm oil, which is associated with deforestation in tropical areas, or meat, which requires incredibly high amounts of water, energy, and crops/ land to produce.

4. Volunteer for the Environment

The state of our environment is such that there is always work to do. Volunteering is one important way in which we can help the environment and inspire others to do the same. It can take many forms, such as saving animals or animal habitats, cleaning urban or wild areas from litter, finding sponsors and raising donations for specific environmental projects, helping to gather products for recycling, etc.

All these activities could be time-consuming and could interfere with college coursework. Sometimes, college homework might prevent you from attending an important event or activity that you planned for much ahead. In such situations or whenever confronted with multiple pressing deadlines, getting help from EduBirdie Canada could be a life-saver. Note that any accomplishments in environmental volunteering could become a strong point in your CV as well as a convincing argument for your future academic or job applications, so they shouldn’t be ignored.

5. Travel Less Using Vehicles

Burning fossil fuels are an important contributor to air pollution (an important cause of disease worldwide) but also to rising CO2 levels, which cause global climate change. Hence, it makes sense to substitute, whenever possible, your trips by vehicle with bike rides or walks. Importantly, air travel typically results in hundreds of kilograms of CO2 per passenger, which represents a much higher environmental footprint compared to land transportation.

Conclusion

We have listed above some key directions in which you should act in order to embrace a greener lifestyle. However, there are many more ways to help the environment. Feel free to check these energy-saving tips for additional advice. Importantly, the same goals could be achieved by using a great variety of paths – the way how you implement your personal environmental plan is up to you. You are highly welcome to come up with creative new ways and share them with your community. The world is in desperate need of solutions that would address the environmental disaster we are witnessing.

Biogas Plants at Akshaya Patra Kitchens

The Akshaya Patra Foundation, a not-for-profit organization, is focused on addressing two of the most important challenges in India – hunger and education. Established in year 2000, the Foundation began its work by providing quality mid-day meals to 1500 children in 5 schools in Bangalore with the understanding that the meal would attract children to schools, after which it would be easier to retain them and focus on their holistic development. 14 years later, the Foundation has expanded its footprint to cover over 1.4 million children in 10 states and 24 locations across India.

Akshaya-Patra-Kitchen-BioGas

The Foundation has centralised, automated kitchens that can cook close to 6,000 kilos of rice, 4.5 to 5 tonnes of vegetables and 6,000 litres of sambar, in only 4 hours. In order to make sustainable use of organic waste generated in their kitchens, Akshaya Patra Foundation has set up anaerobic digestion plants to produce biogas which is then used as a cooking fuel. The primary equipment used in the biogas plant includes size reduction equipment, feed preparation tank for hydrolysis of waste stream, anaerobic digester, H2S scrubber and biogas holder.

Working Principle

Vegetable peels, rejects and cooked food waste are shredded and soaked with cooked rice water (also known as ganji) in a feed preparation tank for preparation of homogeneous slurry and fermentative intermediates. The hydrolyzed products are then utilized by the microbial culture, anaerobically in the next stage. This pre-digestion step enables faster and better digestion of organics, making our process highly efficient.

The hydrolyzed organic slurry is fed to the anaerobic digester, exclusively for the high rate biomethanation of organic substrates like food waste. The digester is equipped with slurry distribution mechanism for uniform distribution of slurry over the bacterial culture.

Optimum solids are retained in the digester to maintain the required food-to-microorganism ratio in the digester with the help of a unique baffle arrangement. Mechanical slurry mixing and gas mixing provisions are also included in the AD design to felicitate maximum degradation of organic material for efficient biogas production.

After trapping moisture and scrubbing off hydrogen sulphide from the biogas, it is collected in a gas-holder and a pressurized gas tank. This biogas is piped to the kitchen to be used as a cooking fuel, replacing LPG.

Basic Design Data and Performance Projections

Waste handling capacity 1 ton per day cooked and uncooked food waste with 1 ton per day ganji water

Input Parameters                      

Amount of solid organic waste 1000 Kg/day
Amount of organic wastewater ~ 1000 liters/day ganji (cooked rice water)

Biogas Production

Biogas production ~ 120 – 135 m3/day

Output Parameters

Equivalent LPG to replace 50 – 55 Kg/day (> 2.5 commercial LPG cylinders)
Fertilizer (digested leachate) ~ 1500 – 2000 liters/day

Major Benefits

Modern biogas installations are providing Akshaya Patra, an ideal platform for managing organic waste on a daily basis. The major benefits are:

  • Solid waste disposal at kitchen site avoiding waste management costs
  • Immediate waste processing overcomes problems of flies, mosquitos etc.
  • Avoiding instances when the municipality does not pick up waste, creating nuisance, smell, spillage etc.
  • Anaerobic digestion of Ganji water instead of directly treating it in ETP, therefore reducing organic load on the ETPs and also contributing to additional biogas production.

The decentralized model of biogas based waste-to-energy plants at Akshaya Patra kitchens ensure waste destruction at source and also reduce the cost incurred by municipalities on waste collection and disposal.

akshayapatra-kitchen

An on-site system, converting food and vegetable waste into green energy is improving our operations and profits by delivering the heat needed to replace cooking LPG while supplying a rich liquid fertilizer as a by-product.  Replacement of fossil fuel with LPG highlights our organization’s commitment towards sustainable development and environment protection.

The typical ROI of a plug and play system (without considering waste disposal costs, subsidies and tax benifts) is around three years.

Future Plans

Our future strategy for kitchen-based biogas plant revolves around two major points:

  • Utilization of surplus biogas – After consumption of biogas for cooking purposes, Akshaya Patra will consider utilizing surplus biogas for other thermal applications. Additional biogas may be used to heat water before boiler operations, thereby reducing our briquette consumption.
  • Digested slurry to be used as a fertilizer – the digested slurry from biogas plant is a good soil amendment for landscaping purposes and we plan to use it in order to reduce the consumption of water for irrigation as well as consumption of chemical fertilizers.

Feedstock for AD Plants

Anaerobic digestion is the natural biological process which stabilizes organic waste in the absence of air and transforms it into biofertilizer and biogas. Almost any organic material can be processed with anaerobic digestion.

Biogas_Plant

Anaerobic digestion is particularly suited to wet organic material and is commonly used for effluent and sewage treatment.  This includes biodegradable waste materials such as waste paper, grass clippings, leftover food, sewage and animal waste. Large quantity of waste, in both solid and liquid forms, is generated by the industrial sector like breweries, sugar mills, distilleries, food-processing industries, tanneries, and paper and pulp industries. Poultry waste has the highest per ton energy potential of electricity per ton but livestock have the greatest potential for energy generation in the agricultural sector.

Agricultural Feedstock

Community-Based Feedstock

  • Organic fraction of MSW (OFMSW)
  • MSW
  • Sewage sludge
  • Grass clippings/garden waste
  • Food wastes
  • Institutional wastes etc.

 Industrial Feedstock

  • Food/beverage processing
  • Dairy
  • Starch industry
  • Sugar industry
  • Pharmaceutical industry
  • Cosmetic industry
  • Biochemical industry
  • Pulp and paper
  • Slaughterhouse/rendering plant etc.

Anaerobic digestion is particularly suited to wet organic material and is commonly used for effluent and sewage treatment. Almost any organic material can be processed with anaerobic digestion process. This includes biodegradable waste materials such as waste paper, grass clippings, leftover food, sewage and animal waste. The exception to this is woody wastes that are largely unaffected by digestion as most anaerobic microorganisms are unable to degrade lignin.

Anaerobic digesters can also be fed with specially grown energy crops such as silage for dedicated biogas production. A wide range of crops, especially C-4 plants, demonstrate good biogas potentials. Corn is one of the most popular co-substrate in Germany while Sudan grass is grown as an energy crop for co-digestion in Austria. Crops like maize, sunflower, grass, beets etc., are finding increasing use in agricultural digesters as co-substrates as well as single substrate.

A wide range of organic substances are anaerobically easily degradable without major pretreatment. Among these are leachates, slops, sludges, oils, fats or whey. Some wastes can form inhibiting metabolites (e.g.NH3) during anaerobic digestion which require higher dilutions with substrates like manure or sewage sludge. A number of other waste materials often require pre-treatment steps (e.g. source separated municipal organic waste, food residuals, expired food, market wastes and crop residues).

Composting in Qatar

Qatar has one of the highest per capita waste generation rates worldwide. In 2012, Qatar generated 8,000 tons of solid waste daily (excluding construction and demolition waste which amounts to 20,000 tons additional waste per day).  This number is predicted to reach 19,000 tons/day in 2032, with an annual growth rate of roughly 4.2%.

Most of these wastes end up in landfills – in 2012, more than 90% of Qatar’s solid waste were sent to landfills although the government is intensifying its efforts to reduce this amount. This percentage is extremely high compared to many industrialized countries in Europe and Asia (e.g. Austria, Denmark, Netherlands and Japan) where less than 10% of solid waste are disposed of in landfills.  These countries have high recycling rates, have invested in technologies that convert waste into energy, and apply composting process to their organic waste, especially food wastes. In some of these nations, as much as 40% of their wastes are composted.

Composting in Qatar

Currently, composting in Qatar is mainly done at the Domestic Solid Waste Management Centre (DSWMC) in Mesaieed, which houses the largest composting facility in the country and one of the largest in the world.  The waste that enters the plant initially goes through anaerobic digestion, which produces biogas that can power the facility’s gas engine and generators, followed by aerobic treatment which yields the final product.

Two types of compost are generated: Grade A (compost that comes from green waste, such as yard/park trimmings, leftovers from kitchen or catering services, and wastes from markets) and Grade B (compost produced from MSW).  The plant started its operation in 2011 and when run at full capacity is able to process 750 tons of waste and produce 52 tons of Grade A compost, 377 tons of Grade B compost, liquid fertilizer which is composed of 51 tons of Grade A compost and 204 tons of Grade B compost, and 129 tons of biogas.

This is a significant and commendable development in Qatar’s implementation of its solid waste management plan, which is to reduce, reuse, recycle and recover from waste, and to avoid disposing in landfills as much as possible.  However, the large influx of workers to Qatar in the coming years as the country prepares to host the World Cup in 2022 is expected to substantially increase solid waste generation and apart from its investments in facilities like the composting plant and in DSWMC in general, the government may have to tap into the efforts of organizations and communities to implement its waste management strategy.

Future Outlook

Thankfully, several organizations recognize the importance of composting in waste management and are raising awareness on its benefits.  Qatar Green Building Council (QGBC) has been actively promoting composting through its Solid Waste Interest Group.  Last year, they were one of the implementers of the Baytna project, the first Passivhaus experiment in the country.

This project entails the construction of an energy-efficient villa and a comparative study will be performed as to how the carbon footprint of this structure would compare to a conventional villa.  The occupants of the Passivhaus villa will also be made to implement a sustainable waste management system which includes composting of food waste and garden waste, which is meant to lower greenhouse gas emissions compared to landfilling.

Qatar Foundation is also currently developing an integrated waste management system for the entire Education City and the Food Services group is pushing for composting to be included as a method to treat food and other organic waste.  And many may not know this but composting can be and has been done by individuals in their own backyard and can even be done indoors with the right equipment.

Katrin Scholz-Barth, previous president of SustainableQatar, a volunteer-based organization that fosters sustainable culture through awareness, skills and knowledge, is an advocate of composting and has some great resources on how to start and maintain your own composting bin as she has been doing it herself.  A simple internet search will also reveal that producing compost at home is a relatively simple process that can be achieved with minimal tools.  At present, very few families in Qatar are producing their own compost and Scholz-Barth believes there is much room for improvement.

As part of its solid waste management plan as stated in the National Development Strategy for 2011-2016, Qatar aims to maintain domestic waste generation at 1.6 kg per capita per day.  This will probably involve encouraging greater recycling and reuse efforts and the reduction of waste from its source.  It would also be worthwhile to include programs that will promote and boost composting efforts among institutions, organizations and individuals, encouraging them with the fact that apart from its capability of significant waste diversion from landfills, composting can also be an attractive source of income.

Note: The article is being republished with the permission of our collaborative partner EcoMENA. The original article can be viewed at this link.